function mix = transformGMM2DRigid(state, mix)

theta = state(3);
rot = [cos(theta) -sin(theta);
       sin(theta)  cos(theta)];

mix.centres = [rot*mix.centres']' + repmat(state(1:2), mix.ncentres, 1);
for i = 1:mix.ncentres
    mix.covars(:, :, i) = rot*mix.covars(:, :, i)*rot';
end
